A portion of the Wiehle-Reston East Station is seen in November of 2013 in Fairfax County. (Matt McClain/The Washington Post)

The Silver Line appears on track to receive a federal loan of nearly $1.9 bil­-
lion to help fund the second phase of the rail project, which will include a stop at Dulles International Airport, officials announced Friday.

The Metropolitan Washington Airports Authority and two of its partners in the $5.6 billion rail project, Fairfax and Loudoun counties, have been asked by the Department of Transportation to apply formally for a federal loan — a sign that they are likely to receive the funds they have requested.

The announcement Friday from members of Northern Virginia’s congressional delegation could signal good news for commuters on the Dulles Toll Road. Officials from the MWAA said the
low-interest federal loan, combined with $300 million in funding from Virginia, could mean that tolls are likely to remain at current levels until 2018.

Tolls have increased for five consecutive years.

“Today’s development represents a significant step forward, and I am pleased that this federal support will allow us to continue moving forward with the project and buy-down tolls for commuters,” said Sen. Mark R. Warner (D-Va.)

Rep. Gerald E. Connolly (D-Va.) said: “Today’s announcement is a huge victory for Northern Virginia and commuters in the Dulles Corridor. It’s shaping up to be an exciting spring for Tysons, Reston and the entire Dulles Corridor.”

The nearly $1.9 billion federal loan still must receive formal approval, which is expected later this year. The amount represents about one-third of the project’s cost.

Sharon Bulova, chairwoman of the Fairfax County Board of Supervisors, said that although there are more steps to complete, Friday’s announcement is a “major milestone.”

“Rail to Dulles is one of the most important and valuable transportation infrastructure projects in the United States,” Bulova (D) said.

Fairfax in particular is counting on the first phase of the rail line, which includes four stops in Tysons Corner, to jump-start the transformation of a traffic-clogged, car-centric area into a pedestrian-friendly, urban oasis.

The money would be provided through the federal Transportation Infrastructure Finance and Innovation Act (TIFIA), which provides direct loans, loan guarantees and standby lines of credit to help finance regional and national transportation projects.

MWAA is responsible for managing construction of the 23.1-mile rail project — one of the biggest infrastructure projects in the country. For the first phase, the Department of Transportation provided $900 mil­lion, but made it clear that federal support for the second phase would come in the form of loans, not grants.

The first phase of the rail project is expected to open this year. Dulles Transit Partners, which is led by construction giant Bechtel, told MWAA officials this month that they think they have completed their work on the first phase of the rail line.

MWAA officials are working to determine whether the project is complete.

If approved, the loan would be one of the largest ever given though the TIFIA program.